L6920 is a high efficiency step-up controller, requiring only three external components to realize the conversion from the battery voltage to the selected output voltage. The start up is guaranteed at 1V and the device is op- erating down to 0.6V. Internal synchronous rectifier is implemented with a 120mΩ P-channel MOSFET and, in order to improve the efficiency, a variable frequency control is imple- mented.